Excessive speed responsive engine governors



April 4, 1967 R. E. YOUNG ETAL 3,312,233

EXQESSIVE SPEED RESPONSIVE ENGINE GOVERNORS Filed Jan. 5, 1964 55 93 ZINVENTORS 5%5eri 5%11/30 65 BY Cyarazzceffi'an AT TORNE Y Patented Apr.4, 1967 3,312,233 EXCESSIV E SPEED RESPONSIVE ENGINE GOVERNORS Robert E.Young, Anderson, and Clarence L. Julian,

Middletown, Ind., assignors to General Motors Corporation, Detroit,Mich, a corporation of Delaware Filed .Ian. 3, 1964, Ser. No. 335,490 2Claims. (Cl. 137-57) This invention relates to engine governors and moreparticularly to the type of speed control for an internal combustionengine employing a fluid operated servomotor for actuating a governorthrottle.

It is common to provide internal combustion engines with a speedgovernor in situations where it is desirable to limit the maximum speedof the engine. Such governors are usually adjustable to govern theengine over a wide range of predetermined speeds and will functioneffectively throughout the governing range. A governor of this type isshown in the United States Patent 2,664,- 867 issued Jan. 5, 1954, tothe assignee of the present invention.

This type of speed governor usually employs a centrifugally unbalancedvalve slidable in a transverse bore in the ignition distributor shaft ofthe engine. The valve 5 in a more or less constant state of motion whenthe engine is running and operates to restrict the air bleed to theservomotor controlling the governor throttle. When a large or suddenengine load decrease occurs, this causes overtravel of the valve to theclosed position suddenly cutting off air to the servomotor. To reducethe hunting condition and the overtravel effect at sudden high speed,the centrifugal valve may be provided with a subsidiary air bypasspassage.

This construction .is the subject of United States Patent 2,828,725issued Apr. 1, 1958, also to the assignee of the present invention.

Experience has shown that a centrifugal governor valve mounted directlyin the distributor shaft is subject to wear after long periods of timedue to the hunting motion which is a condition of its environment. Whenwear occurs, the variable area bleed orifice restrictedby the valveelement tends to permit air leakage resulting in a change in thegoverned speed.

In the improved governor of the present invention, the speed responsivemechanism of the governor is not in tegral with the governor valve thusdoing away with some of the objectionable features of the centrifugallyactivated integral valve. In the present ararngement, a governor shaftcarries a speed responsive unit acting independently to move thegovernor valve according to the engine speed to control the servomotorand the position of the governor throttle.

A more detailed understanding of the invention may be had by referringto the following description and drawings wherein:

FIGURE 1 is an elevation view of the air cleaner and ignitiondistributor areas for an internal combustion engine incorporating theinvention;

FIGURE 2 is an enlarged offset sectional view of the governor mechanismshown in FIGURE 1.

Referring to FIGURE 1, a carburetor is mounted on the engine intakemanifold 12 through an intermediate governor duct 14 and carries an aircleaner 16. A butterfly throttle valve 18 is supported in a carburetorbarrel by a shaft 20 to determine fuel-air flow to the engine below thegoverned speed in accordance with the position of the manual throttlecontrol 22. An air balanced governor throttle valve 24 is supported inthe governor duct 14 by shaft 26 to determine fuel-air flow to theengine in accordance with the engine load to maintain the engine at apredetermined governed speed when the carburetor throttle Valve 18 issufliciently opened for the engine governor to assume control.

Referring to FIGURE 2, actuation of the governor throttle 24 isaccomplished by servomotor 28 which is supported on a column 30 andconnects with a crankarm 32 of the throttle valve. The servomotor 28includes a cylinder 34 forming a collapsible chamber 36 with a flexiblediaphragm 38 which carries a link 40 pivotally connected to the crankarm32 and biased to the governor valve opening position by a tension spring42 connected between the crankarm 32 and a lug 44 within the governorthrottle housing 45. The spring force may be varied by hooking thespring on other lugs 44 thus increasing the tension and making it harderfor the servomotor to close the governor valve.

A passage 46 formed in the column 30 connects the collapsible chamber 36to the governor duct 14 on the engine side of the governor throttlevalve. A conduit 48 also connects with the chamber 36 and to atmosphereby Way of the air cleaner 16 through the speed sensing unit 50 and airbleed conduit 52. J

The unit 50 is mounted directly on the distributor housing 54 carryingthe ignition distributor shaft 55 and includes a body portion 57 havinga bore 58 extending longitudinally thereth-rough and transversely to theaxis of the distributor shaft 55. A governor shaft 60 is journalled atone end of the bore 53 in a coupling and cross shaft bearing unit 62 andat the other in antifriction bearing 64. It is driven at some speedproportional to that of engine speed through the helical geartransmission arrangement 65. The bore 58 is closed at one end by theplate 67 having a central aperture 68 through which one end of thegovernor shaft 60 extends. A splined portion 70 on the governor shaftbeyond the plate 67 carries a yoke element 71 and fly ball weight 72which rotate with the governor shaft. The centrifugally acting weight 72is pivoted at 73 on the yoke element which includes a wing portion 74opposite the weight to act as a counter-balancing mass. A finger 75integrally formed on the weight 72 extends radially inwardly to a pointin alignment with the governor shaft. The end of the governor shaft isformed with a sleeve portion 76 having an axial slot 78 through whichpasses the end of the finger 75. A plunger 79 is slidably received inthe sleeve portion 76 in front of the finger 75.

A cover member 80 for the unit 50 seals with the body portion 57 andincludes a head portion 81 having an elongated bore 82 therein alignedwith the governor shaft 60. Transverse passages 83 and 84 intersectingwith bore 82 are adapted to thre-adably receive fittings on the airbleed conduit 52 leading to the air cleaner 16 and on the conduit 48leading to the vacuum servomotor 28. Passage 33 terminates in an orifice85 substantially larger than the air bleed orifice 86 of the passage 84.

A valve element 83 is slidably received in the bore 82 and is biased inthe valve open position and against the end of plunger 79 by the spring90. Adjustment screw 92 is provided to vary the biasing force applied byspring 90.

The valve 88 is provided to control the amount of air bleed to thevacuum servomotor 28 and thereby vary the position of the governorthrottle valve 24. Air flow through the orifice 86 does not affect thevalve 88 so that the movement of the valve is solely in accordance withengine speed.

With the engine under governor control, the valve 88 decreases air bleedto the servomotor 28 on momentary engine acceleration due to a fallingload thereby occasioning increased vacuum in the servomotor chamber 36which overbalances the spring 42 and moves the governor throttle valve24 toward the closed position reducing fuel-air flow to the engine todecelerate to governed speed. Conversely, the valve 88 increases airbleed on momentary engine decelerations due to an increased load therebyoccasioning decreased vacuum to the servomotor chamber 36 which isovercome by the spring 42 tending to move the governor throttle valve24- toward the opened position increasing fuel-air fiow to the engine toaccelerate the engine to governed speed.

The valve 88, in restricting the air bleed, never entirely closes theorifice 85; hence, as engine speed increases the valve moves to theright against the force of spring 90 in response to the push by theplunger 79 upon command of speed responsive weight 72. A limit stop 91on the weight prevents overtravel. When the governed speed is reached,restriction of the orifice 86 by the valve takes place. Upon a large orsudden load decrease, overtravel of the valve 88 is minimized since itis not directly centrifugally unbalanced. Consequently, an air bleedbypass passage to minimize the effects of overtravel as in theabove-mentioned Patent 2,828,725 is not considered necessary.

More importantly, the disadvantage with the centrifugally unbalancedvalve mounted crosswise directly in the distributor shaft is thetendency to Wear attendant with the constant hunting action of the valvein accordance with the centrifugal forces acting on it. The presentvalve arrangement is less subject to Wear since the valve element is notsliding directly Within the air bleed orifice.

While the preferred embodiment of the invention has been described fullyin order to explain the principles of the invention, it is to beunderstood that modifications of structure may be made by the exerciseof skill in the art without deviating from the intended scope of theinvention as expressed in the appended claims.

What is claimed is:

1. A speed responsive centrifugal governor for an engine having a fluidpressure operated actuator, said governor comprising:

a housing adapted to be mounted on the engine;

a governor shaft rotatably carried by the housing and adapted to bedriven at a speed proportional to engine speed, said shaft having asleeve portion at one end extending coaxially with the axis of rotationand an axially-directed slot in said sleeve portion;

a yoke element rotatably carried by said governor shaft and pivotallysupporting in centrifugally unbalanced flyweight having a fingerextending through said slot into intersecting relation with the axis ofrotation;

said housing having a bore spaced from the yoke element and coaxial withthe axis of rotation and a transverse passage intersecting the bore andcommunicating with the actuator;

a valve element slidably received in the bore, said valve element beingmovable in the bore to meter fluid flow through the passage;

and a plunger reciprocably carried in said sleeve portion and contactingboth said finger and said valve element to provide an actuatingconnection therebetween, the contacts of said finger and plunger and ofsaid plunger and valve element occurring substantially along said axisof rotation whereby frictional loss due to said contacts is minimized.

2. The device of claim 1 wherein said yoke element is splinedlyconnected to said governor shaft to permit ease of disassembly therefromand said yoke element includes a Wing portion oppositely disposed fromthe pivotally carried flyweight to balance the weight thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,502,594 7/1924Spiva 137-57 X 1,627,761 5/1927 WOOls0n 73-550 X 2,157,472 5/1939 Bellis123-103 2,431,816 12/1947 Mallory 123-103 2,583,590 1/1952 Osterhus73-550 X 2,656,174 10/1953 Cr00kst0n 137-33 2,662,512 12/1953 Schaffer123-103 2,664,867 1/1954 Hartzell et a1 123-103 2,828,725 4/1958Hartzell et a1. 123-103 CLEARENCE R. GORDON, Primary Examiner.

WILLIAM F. DDEA, FRED, E. ENGELTHALER, Examiners.

A. L. SMITH, Assistant Examiner.

1. A SPEED RESPONSIVE CENTRIFUGAL GOVERNOR FOR AN ENGINE HAVING A FLUIDPRESSURE OPERATED ACTUATOR, SAID GOVERNOR COMPRISING: A HOUSING ADAPTEDTO BE MOUNTED ON THE ENGINE; A GOVERNOR SHAFT ROTATABLY CARRIED BY THEHOUSING AND ADAPTED TO BE DRIVEN AT A SPEED PROPORTIONAL TO ENGINESPEED, SAID SHAFT HAVING A SLEEVE PORTION AT ONE END EXTENDING COAXIALLYWITH THE AXIS OF ROTATION AND AN AXIALLY-DIRECTED SLOT IN SAID SLEEVEPORTION; A YOKE ELEMENT ROTATABLY CARRIED BY SAID GOVERNOR SHAFT ANDPIVOTALLY SUPPORTING IN CENTRIFUGALLY UNBALANCED FLYWEIGHT HAVING AFINGER EXTENDING THROUGH SAID SLOT INTO INTERSECTING RELATION WITH THEAXIS OF ROTATION; SAID HOUSING HAVING A BORE SPACED FROM THE YOKEELEMENT AND COAXIAL WITH THE AXIS OF ROTATION AND A TRANSVERSE PASSAGEINTERSECTING THE BORE AND COMMUNICATING WITH THE ACTUATOR; A VALVEELEMENT SLIDABLY RECEIVED IN THE BORE, SAID VALVE ELEMENT BEING MOVABLEIN THE BORE TO METER FLUID FLOW THROUGH THE PASSAGE; AND A PLUNGERRECIPROCABLY CARRIED IN SAID SLEEVE PORTION AND CONTACTING BOTH SAIDFINGER AND SAID VALVE ELEMENT TO PROVIDE AN ACTUATING CONNECTIONTHEREBETWEEN, THE CONTACTS OF SAID FINGER AND PLUNGER AND OF SAIDPLUNGER AND VALVE ELEMENT OCCURRING SUBSTANTIALLY ALONG SAID AXIS OFROTATION WHEREBY FRICTIONAL LOSS DUE TO SAID CONTACTS IS MINIMIZED.